Answer: 0.25 m/s
Explanation: Speed = wavelengt · frequency
v = λf and frequency is 1/period f = 1/T
Then v = λ/T = 5 m / 20 s = 0.25 m/s
Answer:
Cool question! First step is to find the time taken to fall
57
m
, then to find the horizontal velocity needed to cover
24
m
in that time. In this case the answer is
7.0
m
s
−
1
.
Explanation:
This is a less typical projectile motion question, but it's still projectile motion. This means the horizontal and vertical directions can be considered separately. We assume that the initial vertical velocity,
u
y
=
0
m
s
−
1
, and we are trying to find the required initial horizontal velocity,
u
x
.
To find the time taken to fall
57
m
:
s
=
u
t
+
1
2
a
t
2
Since
u
=
0
, we can rearrange this to:
t
=
√
2
s
a
=
√
2
⋅
57
9.8
=
3.41
s
The horizontal velocity will be constant (ignoring air resistance), so to cover
24
m
in
3.41
s
will be given by:
v
=
s
t
→
u
x
=
24
3.41
=
7.0
m
s
−
1
Answer link
Answer:
Positive sign for negative velocity and minus sing for positive velocity
Explanation:
In the case of the negative velocity, the sign of the acceleration that reduces its magnitude is the positive sign, since being in the opposite direction to the movement indicates a deceleration or braking. In the case of the positive velocity, the sign of the acceleration that reduces its magnitude is the negative sign, since being in the opposite direction to the movement indicates a deceleration or braking. We observe that there will always be a reduction in the magnitude of the velocity if the acceleration goes in the opposite direction.
The volume is given by:
V = Ad
V = volume, A = surface area, d = depth
Given values:
A = 116214700km² = 1.162147×10¹⁸cm², d = 3940m = 394000cm
Plug in and solve for V:
V = 1.162147×10¹⁸(394000)
V = 4.57885918×10²³cm³
Answer:
vf=at+v0. vf=0
-v0=at
t=-v0/a=(-27m/s)/(-8m/s^2)=3.4s
